1. Field
The present application relates to thermal management and, more particularly, to micro-scale cooling devices that generate ions and electrical fields to motivate flow of fluids, such as air, as part of a thermal management solution to dissipate heat.
2. Related Art
Devices built to exploit ionic movement of a fluid are variously referred to in the literature as ionic wind machines, electric wind machines, corona wind pumps, electro-fluid-dynamic (EFD) devices, electrohydrodynamic (EHD) thrusters, EHD gas pumps and EHD fluid or air movers. Some aspects of the technology have also been exploited in devices referred to as electrostatic air cleaners or electrostatic precipitators.
When employed as part of a thermal management solution, an ion flow fluid mover may result in improved cooling efficiency with reduced vibrations, power consumption, electronic device temperatures and/or noise generation. These attributes may reduce overall lifetime costs, device size or volume, and in some cases may improve system performance or user experience.
As electronic device designers drive to smaller and smaller form-factors, such as in the extremely thin handheld devices popularized by iPhone™ and iPad™ devices available from Apple, Inc., packing densities of components and subsystems create significant thermal management challenges. In some cases, active strategies to exhaust heat to the ambient environment may be required. In some cases, mass transport across a ventilation boundary may be unnecessary, but heat transport within the device may be necessary or desirable to reduce hotspots.
Ion flow fluid movers present an attractive technology component of thermal management solutions. Solutions are desired that allow ion flow fluid movers to be integrated in thin and/or densely packed electronic devices, often in volumes that provide as little as 2-3 mm of clearance in a critical dimension. In particular, solutions are desired that allow dense packing of high-voltage, ion-flux generating EHD components with electronic assemblies that may be otherwise sensitive to electrostatic discharge and or electromagnetic interference. In some cases, solutions are desired that manage or mitigate ozone byproducts of certain high intensity fields and/or discharges.